July 18: First air-conditioned luxury cruise liner is launched in 1931

On this date—July 18, 1931—the SS Mariposa, the first air-conditioned luxury cruise liner, was launched. She was built by the Bethlehem Ship Building Corporation in Quincy, Mass., and became famous for being one of the swiftest and sleekest ships on the Pacific.

The Mariposa was a true luxury ship, with large and elaborate public spaces. But at a time when air conditioning for ocean travel was a novelty, the ship's most luxurious aspect was her air-conditioned first-class dining room. This popular feature made the heat and humidity of the South Pacific and Australia significantly easier to bear.

Like many other passenger ships, the Mariposa was requisitioned in 1941 by the U.S. government and for the next five years was used as a troop ship. After she was returned to her owners in 1946 she was deemed too damaged to be refitted and reused, and was eventually put on the market in 1953.